
.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}
.m-10 { margin: 10px }
.m-20 { margin: 20px }
.m-30 { margin: 30px }
.mt-10 { margin-top: 10px; }
.mt-20 { margin-top: 20px; }
.mt-30 { margin-top: 30px; }
.mb-10 { margin-bottom: 10px; }
.mb-20 { margin-bottom: 20px; }
.mb-30 { margin-bottom: 30px; }
.ml-10 { margin-left: 10px; }
.ml-20 { margin-left: 20px; }
.ml-30 { margin-left: 30px; }
.mr-10 { margin-right: 10px; }
.mr-20 { margin-right: 20px; }
.mr-30 { margin-right: 30px; }